The dated entries in this notebook cover the period January-February 1879. The earliest entries may be from December 1878. Most of the entries are by Edison, Charles Batchelor, and Francis Upton. There are also entries by John Kruesi. All of the material relates to experiments on electric lighting. Included are notes on metals for filaments; calculations and drawings of generators; and notes and calculations about electric power distribution systems. The book contains 152 numbered pages. Following page 33, the left-hand pages are unnumbered.

Blank pages: 20-21, 24-25.